In this course, we've been talking about principles for designing for humans. We started from what psychology tells us about how people perceive and process and remember information, and then drawn connections to principles for how to design effective user experiences. Most of what we've talked about in this course focuses on the usability of user interfaces. As we know, usability is one of the core elements of user experience. Even just with respect to usability, there is a lot more that we could have covered, but we didn't have time to get to in this course. To go deeper into this area, you might pick up a copy of Don Norman's Design of Everyday Things which we talked about in some depth throughout this course. In the actual book, he goes into more depth on the stages of action and the gulfs of execution and evaluation, and also more depth on the principles to support discoverability like feedback and constraints, affordances, and so forth. Another book that I find really useful is, Designing with the Mind in Mind, by Jeff Johnson. In this book, he starts with the principles of human psychology including, severally the ones that we talked about and other ones as well, and maps them into concrete design do's and don'ts with lots of great examples. If you want more on the design principles for creating good user interfaces without as much depth on the science behind it, Steve Krug's, Don't Make Me Think, is a very approachable, very helpful reference for specific design principles around web and mobile usability. But usability is only one component of user experience, and unfortunately, we didn't have enough time in this course to get into all of the different components. When thinking about value, unfortunately, there isn't much we can say that generalizes across the board to different types of people. Different people have different needs, and for each system that you're working on, you need to understand those specific needs in order to make sure that the system addresses the needs that the users have. So, while there are no magic solutions, there are well-known methods that help us understand users needs and how to design systems that satisfy them. One text that I recommend in this regard is, Observing the User Experience, by Goodman Kuniavsky and Moed. While we haven't talked about how to design for desirability in this course, it is an important topic and I'd like to give you some suggestions about how you might start looking into and thinking about this topic with regards to user experience. One suggestion is another book by Don Norman, a sort of follow-up to The Design of Everyday Things, where he talks about how users respond emotionally to designs. He talks about, for example, three levels of emotional response that we have, ranging from the visceral, which is the fast, primitive response that we have to things like colors and motion, and how that impacts, and emotional response that users have. The behavioral level, which is based on use, which is most closely related to the types of usability focused principles we've been talking about here, to the reflective level, which is based more on associations that users make between a system and things like their underlying values, or other systems that they use or have used in the past, or reflections on themselves and their identity, and how a system does or does not contribute to their sense of self. A number of authors have written about the role of aesthetics and beauty in user experience design. One good example is an article that Marc Hassenzahl has written for the Encyclopedia of Human-Computer Interaction, which is on the Interaction Design Foundation website. You can find the link to this at the bottom of the screen. He talks about how experience is an inseparable meaningful whole, and how experience becomes relevant through remembered stories. So, the stories that we tell ourselves about our experiences become the meaning of those experiences. He also talks about how there's more to experience than can be understood by looking at product features or by just looking at things like usability. Increasingly, when we design interactive systems, we're not just designing products that people use, but we're actually designing and sustaining relationships between the provider of the service and the user. Many designers are talking about service design as a complement to user experience design, that looks specifically at those relationships between a service provider and a user, and maps out things like the customer journey that describes how a user starts to use a service, how they progress through using the service, and even how they come to the end of their relationship with the service provider. Service design also gives us the notion of multiple touch points, different user interfaces or different physical interactions that users might have with a service provider, and how those touch points need to be designed to be consistent with each other and to provide a complete picture of the relationship. The fourth component of user experience is adoptability, which refers to how easy it is for users to find and access and begin using a product or service. An important aspect of adoptability is accessibility, how easy is it for users with different motor and sensory and cognitive capabilities to access a system and get done what they need to get done? Accessibility is a huge area, it's probably worthy of its own course at least if not several courses, even the subfield of web accessibility, so just, how do you design websites so that people with different capabilities can access them is big and constantly evolving? As a way to get started thinking about accessibility and how you can include accessibility in designs that you do, I can recommend this video from the University of Washington. It focuses specifically on web accessibility, but a lot of the principles that they describe apply more broadly to other types of systems that you might develop as well. In this course, we've been talking about principles for designing for humans. We've done that through understanding human perception and cognition. How do people perceive the world around them? How do they make sense of that information and remember it for later use? Based on that knowledge, we've been looking at design principles that you can employ for making sure that systems that you design are usable by people. We've introduced an inspection method, heuristic evaluation, that you can use right now to improve systems that you're working on, and I've given you some pointers for how you can explore this very large topic further. Thanks for being part of this course, and I look forward to seeing you in future courses as well.